This invention relates to a support apparatus, and more particularly to a support apparatus for supporting a handpiece for laser surgery.
The construction of a conventional supporting device for supporting a handpiece 5 is shown in FIG. 1. In the drawing, a CO.sub.2 laser oscillator and control instrument thereof are enclosed in a box-shaped main body 1. A support post 2 is vertically supported by the main body 1 so as to extend upwards. A movable arm 3 comprising a vertical portion 3a and a horizontal portion 3b connected by a universal joint 6 is pivotably supported by the end 8 of the support post 2. A handpiece 5 is pivotably supported by the end of the vertical portion 3a of the arm 3 which is remote from the joint 6. At the other end of the arm 3 is mounted a counterweight 4 which enables the horizontal portion 3b of the arm 3 to maintain a horizontal attitude when the handpiece 5 is not in operation. A surgical operating table 7 is also illustrated in the drawing.
Next, the operation of this device will be explained. The movable arm 3 is pivoted about the center of the end 8 of the support post 2, which is bent at the joint 6, and is moved to a desired position of the operating table 7 by an operator (not shown). When the unillustrated CO.sub.2 laser oscillator is turned on, a laser beam generated by the laser oscillator passes through the support post 2 and the arm 3, and is emitted from the hand piece 5 and is used for surgery.
However, in the conventional support device, the horizontal portion 3b of the movable arm 3 must be quite long for it to extend to any portion of an operating table 7. Therefore, the movable arm 3 is subjected to a large shear force and large bending moment at the center of the end 8 due to its own weight. Therefore, the mechanical strength of the movable arm 3 must be increased to keep the arm 3 straight, which requires that the movable arm 3 be of sturdier construction with thicker walls. However, this increases the weight of the movable arm 3 and makes the handpiece 5 difficult to maneuver.